Video terminals of various configurations are well known and widely used. Since the introduction of the microprocessor video terminals have become "intelligent"; that is video terminals no longer rely entirely on a remote processor to provide data entry, data handling and terminal features such as underline, blinking underline, reverse video, split screen, etc.
Early video terminal systems required at least 100 Medium Scale Integration (MSI) and Small Scale Integration (SSI) devices to implement a relatively small number of terminal features. An example of one early terminal is the Lear-Seigler ADM-3. Second generation video terminal display systems began using a microprocessor in conjunction with Large Scale Integration (LSI) video controllers which provided many necessary functions, such as sync timing and memory addressing, previously done in MSI and SSI. An example of such a second generation video controller is the SMC CRT 5027 provided by Standard Microsystems Corporation of Hauppauge, New York. The use of a microprocessor in conjunction with an LSI video controller also provided a means whereby "intelligent" features such as character and line editing and other word processing features could be incorporated into the display system. Second generation display systems however continue to experience many unsolved problems. These problems include: